On the way to finding salt resistant wheat

16 March 2020 - Published by Dorte Storper
As salty soils increase in number due to climate change, there is a need to find cultivable crops that can withstand salt. Researchers at the University of Gothenburg and Lund University, both members of the SalFar partnership, are now well on their way towards that goal.

For farmers, who largely use sea-close soils, to survive, salt-resistant crops are required. In a new study, which is based on agriculture in Bangladesh, researchers at the University of Gothenburg and Lund University present 20 new so-called lines of wheat that exhibit salt-resistant properties.

“To obtain wheat, which can withstand salt, we have used what is called molecular breeding, which entails the addition of chemicals to wheat seeds in the laboratory. It is a method that has been used since the 1950s and is not regulated as genetically modified organisms, GMOs”, says Henrik Aronsson, professor at plant molecular biology at the University of Gothenburg.

The method produces random mutations in wheat seeds, i.e. changes in the wheat's DNA chain. The wheat seeds that exhibit properties most resistant to salt are then used for further processing to the next generation. From each processed wheat seed there is an individual plant called a line.

“Getting tough seeds is an extensive job. We started our research program seven years ago with Professor Olof Olsson at Lund University. We had 30,000 lines, which over time became a few thousand. Seventy of them proved promising and now we have produced around 20 lines that are better than the others”, says Henrik Aronsson.

Knowledge of salt resistance depends on several properties

The salt resistance of the wheat is a complex concept. Different genes can affect tolerance in different ways, for example, the ability of the plant to absorb water or the plant's tolerance to salt.

“When we got salt-resistant plants, we did not know what genes had changed. We have to map this out in retrospect and compare it with the original variety”, says Johanna Lethin, a PhD student in the research project at the University of Gothenburg.

Today, about 95 percent of the wheat's genome is mapped. According to the researchers, there are several ways to go in order to reach the goal of finding cultivable wheat that can withstand salt water.

“And different characteristics are required for wheat cultivation in different parts of the world as some wheat varieties that work in Bangladesh, might not work in Australia, the Netherlands and Egypt that also have problems with salty soils”, says Henrik Aronsson.

So, while the population is increasing globally, the cultivable land is decreasing. The UN estimates that 70% more food will be needed in 2050 to support the entire population of the earth. Being able to grow and water with brackish water is also a future challenge (read more about this topic here).

Henrik Aronsson points out that due to climate change there is a need for salt-resistant wheat in other parts of the world as sea level rise also will affect coastal strips of the North Sea Region countries.

The lines have been tested within the Saline Farming (SalFar) project and the best lines are to be crossed with the best Swedish wheat varieties this Spring. Who does not remember the extremely hot summer 2018 in Europe, which led to much smaller harvests and lack of fresh water? Thus, use of salt tolerant crops in combination with brackish watering could be one option in the future under such conditions.

The study has been published in BMC Plant Biology.